Notices
Series I Tech Garage The place to discuss anything technical about the RX-8 that doesn't fit into any of the categories below.

Clutch/Transmission issue

Old 10-14-2012, 05:25 PM
  #1  
Made in England
Thread Starter
iTrader: (5)
 
wrightcomputing's Avatar
 
Join Date: Oct 2010
Location: Sarasota
Posts: 738
Likes: 0
Received 1 Like on 1 Post
Clutch/Transmission issue

I am having some issues with my clutch/transmission.
Symptoms
  • Car lunges forward about an inches when engaging 1st gear from a stand still - Happens every time and also happens with other gears
  • Grinds and goes into gear when down shifting to 2nd (rev matching) - about 1 in 5 times
  • Grinds and locks out when shifting to 2nd from 1st at high speed (autocross launch) when you shift too quickly - usually co-drivers but occasionally it happens to me also
  • Grinds when shifting into 5th occasionally.
  • The car seems to move forward in neutral - I had the car on jack stands and in neutral the wheel turn forwards. I can stop the movement by touching the wheels with my hands but they definitely move.
Steps takes to resolve
  • Stainless steel clutch line installed and bled clutch system
  • changed transmission oil (I used mobil, based on research I will switch to Redline or Eneos)
  • Adjusted clutch pedal up and down (no real change to the grinding)
Other possible solutions :-(
  • new transmission
  • better oil


I think changing the Oil may help with some of the grinding but would that make any difference to the car lunging forward.


As always any help is greatly appreciated.
wrightcomputing is offline  
Old 10-14-2012, 08:10 PM
  #2  
Made in England
Thread Starter
iTrader: (5)
 
wrightcomputing's Avatar
 
Join Date: Oct 2010
Location: Sarasota
Posts: 738
Likes: 0
Received 1 Like on 1 Post
Originally Posted by Charles R. Hill View Post
What is meant by this? Did you adjust the pedal height or the pedal free-play?
I adjusted the free play to virtually zero and the added about 4 turns to increase the free play. It did not seem to effect the grinding either way.

It is feel like the Clutch is not full disengaging when the pedal is pressed.

I forgot to mention that I have the Exedy Stage 1 Clutch (Same as OE with more pressure) which is about a year old maybe 15K.
wrightcomputing is offline  
Old 10-14-2012, 09:20 PM
  #3  
Registered
iTrader: (1)
 
Sugarfree135's Avatar
 
Join Date: Sep 2012
Location: Grand junction CO
Posts: 148
Likes: 0
Received 0 Likes on 0 Posts
I wonder if your clutch fork may be bent not allowing full disengagement. Regardless the fact is the clutch is not disengaging fully. If you put it in nuetral and rev it does it move forward? The only thing I could suggest is replacing the cmc and slave. It should be done when you replace the clutch anyway most people dont realize this. It especially holds true when upgrading to a stiffer pressure plate because the system is stressed more upon installation of the new clutch and pressure plate.
I've seen this happen on one of my old dsm's and on a close friends civic si. It's not that expensive or difficult to fix don't worry ;-)
Sugarfree135 is offline  
Old 10-14-2012, 10:03 PM
  #4  
Made in England
Thread Starter
iTrader: (5)
 
wrightcomputing's Avatar
 
Join Date: Oct 2010
Location: Sarasota
Posts: 738
Likes: 0
Received 1 Like on 1 Post
Originally Posted by Sugarfree135 View Post
I wonder if your clutch fork may be bent not allowing full disengagement. Regardless the fact is the clutch is not disengaging fully. If you put it in nuetral and rev it does it move forward? The only thing I could suggest is replacing the cmc and slave. It should be done when you replace the clutch anyway most people dont realize this. It especially holds true when upgrading to a stiffer pressure plate because the system is stressed more upon installation of the new clutch and pressure plate.
I've seen this happen on one of my old dsm's and on a close friends civic si. It's not that expensive or difficult to fix don't worry ;-)
Thanks for the advice. I will replace the Master and slave, can you get in to the slave without lowering the Transmission its a bit tight up there?
wrightcomputing is offline  
Old 10-14-2012, 10:24 PM
  #5  
Registered
iTrader: (1)
 
Sugarfree135's Avatar
 
Join Date: Sep 2012
Location: Grand junction CO
Posts: 148
Likes: 0
Received 0 Likes on 0 Posts
I've had my 8 for a little over a month so I'm not sure on this car lol From what I saw before you should be able to get to it as I could see it but that doesn't mean anything :-P lol
Sugarfree135 is offline  
Old 10-16-2012, 07:23 AM
  #6  
Registered
iTrader: (1)
 
Sugarfree135's Avatar
 
Join Date: Sep 2012
Location: Grand junction CO
Posts: 148
Likes: 0
Received 0 Likes on 0 Posts
Good point Charles I had forgotten about that issue on these cars.
Sugarfree135 is offline  
Old 10-16-2012, 12:56 PM
  #7  
Moder8
iTrader: (1)
 
04Green's Avatar
 
Join Date: Aug 2009
Location: Oviedo, Florida
Posts: 2,548
Received 32 Likes on 22 Posts
Also, that clutch will require you to raise the pedal. I think free-play is the adjustment farthest from the firewall, pedal height is the one closest. I have that clutch and had to mess with both.

Just be happy the damn thing does not release itself at 8,000 rpm... I had to take mine back out and shim it.

The move in neutral thing is interesting though... Maybe really dirty or sticky oil?
04Green is offline  
Old 10-16-2012, 05:58 PM
  #8  
Made in England
Thread Starter
iTrader: (5)
 
wrightcomputing's Avatar
 
Join Date: Oct 2010
Location: Sarasota
Posts: 738
Likes: 0
Received 1 Like on 1 Post
Originally Posted by 04Green View Post
Also, that clutch will require you to raise the pedal. I think free-play is the adjustment farthest from the firewall, pedal height is the one closest. I have that clutch and had to mess with both.

Just be happy the damn thing does not release itself at 8,000 rpm... I had to take mine back out and shim it.

The move in neutral thing is interesting though... Maybe really dirty or sticky oil?
It is really slight hardly noticeable but it is there and it does not increase if I rev the engine. I think I need to adjust the clutch some more and I believe there is still some air in the line so I will bleed it again at the weekend once it has settled.

I have ordered a new CMC so I will install that and see if makes a difference.
wrightcomputing is offline  
Old 10-20-2012, 11:38 AM
  #9  
Made in England
Thread Starter
iTrader: (5)
 
wrightcomputing's Avatar
 
Join Date: Oct 2010
Location: Sarasota
Posts: 738
Likes: 0
Received 1 Like on 1 Post
Well I have changed the Clutch Master Cylinder and bled the system. heT car is still rolling forward in Neutral, its really weird because if I rev the engine it does not affect the speed at which the car rolls forward which is very slowly.

I have checked the brake pedal assembly and there are no signs of cracks or bending or anything else that would affect the the clutch operating correctly.

The car still grinds in 2nd gear when shifting down from a higher gear.
wrightcomputing is offline  
Old 10-20-2012, 12:03 PM
  #10  
Modulated Moderator
iTrader: (3)
 
dannobre's Avatar
 
Join Date: Feb 2004
Location: Smallville
Posts: 12,809
Received 97 Likes on 94 Posts
The only things that would allow forward movement in neutral are friction from the oil transferiing power to the final gears.....or something in the transmission rubbing/bent that is allowing the transfer across the gear train.

The grinding going into gear, and on shifts could be a syncro or a problem or a problem with the clutch dissengaging completely as long as the driver imput is correct


With the gear oil that I run...on a lift with the tranny cold...the rear wheels will turn slowly until the oil warms up considerably....
dannobre is offline  
Old 10-20-2012, 12:13 PM
  #11  
Made in England
Thread Starter
iTrader: (5)
 
wrightcomputing's Avatar
 
Join Date: Oct 2010
Location: Sarasota
Posts: 738
Likes: 0
Received 1 Like on 1 Post
Good to know about the transfer to the higher gears with the cold oil, that makes sense. I will get some redline MT90 and try to put that in after that my only other option is the slave cylinder, then I have to crack open the tranny to check for a bent fork or forked transmission.
wrightcomputing is offline  
Old 10-20-2012, 12:19 PM
  #12  
Modulated Moderator
iTrader: (3)
 
dannobre's Avatar
 
Join Date: Feb 2004
Location: Smallville
Posts: 12,809
Received 97 Likes on 94 Posts
It sounds to me like your second gear syncro is done as well
dannobre is offline  
Old 10-20-2012, 05:26 PM
  #13  
Registered
 
Join Date: Nov 2011
Location: Edmonton, Alberta
Posts: 129
Likes: 0
Received 0 Likes on 0 Posts
What is the best way to tell if you need to have the clutch shimmed if you’re installing a new clutch at the moment? Or do you find out when you drive it?
NO_PSTNS is offline  
Old 10-20-2012, 05:39 PM
  #14  
Made in England
Thread Starter
iTrader: (5)
 
wrightcomputing's Avatar
 
Join Date: Oct 2010
Location: Sarasota
Posts: 738
Likes: 0
Received 1 Like on 1 Post
Originally Posted by dannobre View Post
It sounds to me like your second gear syncro is done as well
If the syncro is done I need a new transmission correct?
wrightcomputing is offline  
Old 10-22-2012, 12:39 AM
  #15  
Registered
iTrader: (1)
 
Sugarfree135's Avatar
 
Join Date: Sep 2012
Location: Grand junction CO
Posts: 148
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by wrightcomputing View Post
If the syncro is done I need a new transmission correct?
No sir not at all lol just a tear down and replacement. Might as well do them all at the same time and freshen up bearings and etc. but it all depends on how much money you want to spend ya know. Syncro is an easy fix though, more labor intensive than anything else :-P
Sugarfree135 is offline  
Old 10-22-2012, 06:50 AM
  #16  
Made in England
Thread Starter
iTrader: (5)
 
wrightcomputing's Avatar
 
Join Date: Oct 2010
Location: Sarasota
Posts: 738
Likes: 0
Received 1 Like on 1 Post
Originally Posted by Sugarfree135 View Post
No sir not at all lol just a tear down and replacement. Might as well do them all at the same time and freshen up bearings and etc. but it all depends on how much money you want to spend ya know. Syncro is an easy fix though, more labor intensive than anything else :-P
Do you know how much the parts will be to for the synchro and bearings. I found a kit for $1300 and $950 which seems very expensive. I can get a replacement series 1 transmission for about $800 or preferable a series 2 for about $1200 and then I don't have to worry about making any mistakes.

I also think this is a job I need to do myself as taking of the tranny is lots of hours labor before any work is even done to it, I have taken it off before so it is no big deal. I would also change the clutch and flywheel too if I had it open so that's an additional $400+ dollars
wrightcomputing is offline  
Old 10-22-2012, 07:15 AM
  #17  
Moder8
iTrader: (1)
 
04Green's Avatar
 
Join Date: Aug 2009
Location: Oviedo, Florida
Posts: 2,548
Received 32 Likes on 22 Posts
@ No_Pstns... On stack height....

When you take it apart, observe the slight dome formed by the fingers in the center of the pressure plate before you remove it from the flywheel. If you can measure it at the center most part of the finger, and at the edge to get the profile, great, if not, take a picture from an angle. You want about the same level of doming (crowning?) with the new one. If they are flatter, that is where the issue can come in. Mine were pretty flat, with the washers / spacers the dome came back. I have an Exedy Stage 1.

FWIW, In hind sight, I would rather have put in the OEM style for a tad lighter pedal, but it is what it is. I did not consult the group before the purchase. I am incredibly happy with the light flywheel thought.
04Green is offline  
Old 10-22-2012, 03:28 PM
  #18  
Modulated Moderator
iTrader: (3)
 
dannobre's Avatar
 
Join Date: Feb 2004
Location: Smallville
Posts: 12,809
Received 97 Likes on 94 Posts
The syncros aren't that expensive to replace if you can do it yourself...but the labor to have someone else do it is where it gets pricey.

I think that the parts to do the bearings and syncros is only a couple of hundred $ if the gears are all OK
dannobre is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
JimmyBlack
Series I Major Horsepower Upgrades
270
03-06-2019 10:56 PM
LB2739
New Member Forum
4
09-13-2015 09:16 AM
Irvinb16
New Member Forum
5
09-11-2015 10:27 PM
tgaffner
New Member Forum
3
09-07-2015 08:49 PM


Thread Tools
Search this Thread
Rate This Thread
Rate This Thread:
You have already rated this thread Rating: Thread Rating: 0 votes,  average.

Quick Reply: Clutch/Transmission issue


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.